This invention relates to liquid purification systems and, more particularly, to an improved vacuum distillation system for inexpensive desalination of seawater or sterilization of any contaminated liquid, such as sewage or chemical waste.
One of the major problems facing future generations is polluted water. Increasing world population and rapid industrial growth combine to cause tremendous contamination problems in the world's rivers, lakes and oceans with an infinite variety of chemical and biological substances. This water must be cleansed before major health problems occur "down the line" or the fish and animal life, as we know it, are threatened.
Another related problem is the lack of potable water, both now and in the future. On land, many areas are arrid or suffer periodic droughts; and at sea, large ships (such as oil tankers) must often carry a huge supply of water for both boiler use and drinking. Clearly, purifications systems would be useful if they could quickly and economically provide abundant amounts of fresh water from seawater or sewage.
Since seawater is almost inexhaustable, desalination systems have been tried for years. However, they have not found widespread acceptance in industry or public use because they are generally bulky and not cost effective. Further, unless they are huge, they normally produce only small quantities of water daily.
One tried type is the vacuum distillation concept described in U.S. Pat. No. 3,558,431 to Foley et al. and U.S. Pat. No. 3,234,109 to Lustenader. Both patented systems utilize the same "vacuum distillation" concept and employ similar basic structure. A vertically extending evaporation or separation chamber is connected in fluid communication with a vertical condensing or product chamber; the chambers are placed under a low pressure by a vacuum pump in the product chamber; and a refrigeration unit is employed with its hot condensing coil located in the system's separation chamber and its cold evaporator coil located inside the product chamber. Seawater can be introduced into the evaporator chamber, where it will boil and evaporate at a low temperature (received from the hot condensing coil of the refrigerator) due to a partial vacuum created by the pump. From there, the vapor rises and hits a plurality of baffles. Particulate hits the baffles and falls back into the reaction chamber, while the rest of the "distillate" vapor flows into the product chamber where it is condensed by the cold coil of the refrigerator as purified liquid.
Theoretically, a vacuum distillation system should be able to both desalinate seawater and purify any contaminated liquid, such as water from a polluted river. However, while commercial versions can achieve this to a limited degree, they have significant commercial drawbacks. For example, prior systems are bulky because their vertical separation and product chambers must be at least 20-40 feet high to avoid undesired splash of the boiling contaminated liquid through a system's baffles and to minimize re-evaporation of the purified liquid collected in the product chamber.
Accordingly, it is the principal object of the present invention to provide an improved vacuum distillation system that overcomes the drawbacks of the prior art.
It is therefore a main object to provide a compact vacuum distillation system that can inexpensively purify any contaminated liquid, including seawater, sewage and chemical waste.
It is another object to provide a purification system that readily separates particulates from the purified liquid for recovery or disposal.
It is another object to provide a vacuum distillation system that is inexpensive to design, yet extremely safe and durable to use.